At the beginning of the story, Nnaemeka describes his cultural upbringing to his fiancée, Nene. Nnaemeka and Nene are engaged to be married, and Nnaemeka is trying to explain to Nene why he hasn't yet written to his father to tell him about the engagement. Nnaemeka says that his father will be upset, because he is engaged to be married to someone who is not in the same tribe as him. Nene asks, "But why?" She is described as "a little surprised" that Nnaemeka's father will not be happy to hear that his son is engaged, even if it is to someone not in the same tribe as him.
Nnaemeka tells Nene that he thinks she is surprised because she has "lived in Lagos all [her] life, and ... know[s] very little about people in remote parts of the country." Nnaemeka is saying, in other words, that Nene is naive when it comes to her understanding of the cultural upbringing that he and other people from the remote parts of the country experience. This naivety is confirmed by the narrator, who says that to Nene, "it had always seemed something of a joke that a person's tribe could determine whom he married." This seems like "a joke" to Nene because she has been raised in "the cosmopolitan atmosphere of the city."
Towards the end of their conversation, Nene says to Nnaemeka, "Come on then, be a good boy and send him a nice lovely letter." The language here is meant to be playful and teasing, and it suggests that Nene does not take the customs of Nnaemeka's cultural upbringing very seriously. She doesn't take them seriously because she does not, at this stage, believe that they can really be as strict and, from her perspective, as regressive as Nnaemeka implies.